crampton



' 3 1 May 927 G. s. CRAMPTON TRIAL LENS MOUNTING FOR OCULISTS AND OPTICIANS Filed June 5. 1922 l/VVEA/Tdl? 5. Chan:

Geory By Patented ay .1927; t

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if N Objects ofthe present invention arey first,

to provide'foriaccurately readingthe scale which indicates the-position of'the axis of f the vcylindrical lens; second; to' accomplish 5 this object and at th sam'e time provide for a a broad surrounding ring .toftake hold' ofj Qwi'thout danger ofsmearing the lens; third,

I to arrange the scaleganddaxis :markings at a considerable distance from the center of in the lens and fourthyto provide an improved metal mounting or cell. for a cylindrical trial lens which obviates defects and difii culties heretofore encountered and facility and accuracy in use.

Theiinvention will be, claimed at the end insures hereof but will be first described in connecfl tion with the embodiment ofit chosen from I other embodiments for the sake of illustr'a tion in the accompanying drawing forming part hereof and in which- Figure 1' is a front v1ew,'

or cell embodying"features of the invention.

the same. s

Fig. 3 is a rear view of the cell or mounting, and

Fig. 4-. is

larger scale of parts of the cell or mounting and of the driving wheel.

,QReferring to the drawingsythe metallic mounting or cell for a cylindrical trial lens 1 comprises a centrall ject ing annular hub 3 provided with axis marking 4 and havingon the rim of the hub a marginal projecting flange '5. The bore of the disk is provided with a lens-bezel 6,

as double sloped as'at' 7 The face ofthe disk opposite therhub 3 is countersunk as at8 and may be circularlyor otherwise a driving wheel of a trial frame, and the arc v plate and the driving wheel are usual provisions of a trial frame which is too well understood to require a detail illustration or.

description. However, in the present case the rim of the-wheel'll is grooved force- 7 operation withthe sloping rim 7 of the disk. The groove in the wheel is shown as V-shaped in cross-section and the rim of the disc 2 isshown asof the form of 1a trunca d pyramid in radial section.

, drawn toan enlarged scale, showing parts of a trial frame and a cylindrical trial lens mounting f Fig. 2 is a'transverse sectional view of.

a sectional view drawn to a still perforated metal' disk2 having on'one ace (a laterally pro-f Fig. 4, andtherim of the disk is shown chased as at 9. 10 is "a graduated arc plate, 'which is generally U-shaped,-, and 11 is a In use the bandof meta-l provided around the lensiswi'de enough to afford a good finger gri for placing the lens" mounting or cell in and removingit*froin the trial frame.

The countersunk face affords 'a' good finger hold which by chasing isfi'mproved. The a hub, 01', moref'accurately the periphery of the hubisfloffcomparatively large diam: etersofthat the markings onthearcplate 10 need notfbe fine orclosetogether.= The hub lies flush with the surface ,of the arc plate, see Fig. 2, so that the axis marking 4 and the graduations on the arcplate come in close proximity and alignment .and there} fore can be accurately and easily read, parallaxbeing entirely avoided. The tongueand-groove provisions between the rims of the wheel 11 and cell or mounting 2 insure accurate turning of the cell or mounting without; danger of. relative slipping. The flat part of the lens may well be mounted toward the. front of the mounting or cell.

It may be said that the rim of the hub confrontsthe rimofthe arc plate, and the flange 5 and back of the arc plate abut flatwise and the thickness of the lens may prov jectbackward leaving a flat face of the lens I at thefront, or either or both surfaces 0 thelens maybe curved asdesired.

In the use of the 'word'metal in connection with the lens holding rim I do not intend to imply that the rim isinecessarily I of metal because other suitablematerial, as celluloid, wmight be substituted for metal and of course a lens-bezel is an example of means for securing the lens in the rim. :It will be obvious to thoseskilled in the 'art to which the invent-ionrelates that modifications may be made in details of construction and arrangelnent' without departing "from the spirit of the invention which is not limited .as to thosematters or otherwisethan asthe prior art and the appended claims may requlre.

lclaimzfl 1. A mountin disk having on one face a laterally projecting annularhub provided with axis mark- Ii gand having on the rim of the hub a marv t I ginal projecting flange providing arfinger vgmp' 2. A mounting for a trial cylindrical lens comprising a centrally apertured disk provi-ded on'the surface of its bore with. a lensbezel and at its rim with a double slope and or cell for a cylindrical trial lens comprising a centrally apertured ,the axisof the disk.

having atpneface an annular hub presentits front face with graduations, and a lens ing aflflat surface'ifor axis inarking and -hav-- moun; ting or'cell comprising a centrally ing its other face countersunk. apertured disk having'on one of its faces a 3. A mounting for a cylindrical 'trial lens" laterally projecting annular hub provided comprising a metal 'disli liaving 'a centralwith axis markingsandarranged substantialopening in whiclrthelens is mounted and 1y fiush with the front face of the plate a double beveled peripherymw radial sec-" *andhaving bl'lthTlllIOlEfl'lG hub a marginal tion of which is a truncated pyramid. the projecting circular flange abutting fiatwise apex of which is at a -definite distance from on the rear face of the plate.

K 6.111 a ;trial frame, theoombinationof a Q lpln a trial framethe combination of a lensflaolder,including a driying; wheel and graduated arc plate and a trial-cylinder. lens a. graduated generally U-shaped arc plate, mounting or cell comprisinga centrally per-c and a centrally. perforated l-disk hayin'g rim forated disk revolublein the frame and havcontact v.wit h/che wheelland provided on one ing onone facea p rojecting mnnular.liub face with a cylindrical'hub fluslv'with the substantiallyflushjwith the surface of the are are plate landqhavingl axis ,markings,-there gplate and hayin'g an axis marking. l beingitongue-and-groove provisions between 5aln i atrialiframeihercombination of a, the rims ofthe disk andwheel. :generally.'U-shaped' arcs-plateT providedi on v :GEQRGE S1 CBAMPTON. 

